The present invention relates generally to intraluminal and endoluminal drug infusion devices, and in particular, to low cost methods and apparatus for modifying and re-using catheters, including balloon catheters, for use in infusing drugs or other therapeutic agents.
In recent years it has been discovered that the intraluminal or endoluminal infusion of drugs can significantly improve the results of certain non-invasive medical procedures. For example, it has been determined that infusion of drugs such as heparin or anti-inflammatory, thrombolytic or antibody products, after an angioplasty procedure, can reduce the risk of restenosis by preventing a proliferation of the cells that may cause such restenosis.
Devices have therefore been developed to provide a controlled delivery of drugs, either intraluminally or endoluminally, and which are inserted into the patient""s vascular system subsequent to some other procedure involving catheterization. The infusion of drugs into the wall of a body vessel, for example, by means of an inflatable angioplasty balloon, is practicable and has been experimentally tested. Such techniques are described, for example, in the Journal of the American College of Cardiology, 1990:15:475 and Circulation, 1992:86:1-380.
In a typical less-invasive catheterization procedure, for example, a balloon angioplasty procedure to restore patency to a body vessel or a stent delivery procedure to prevent restenosis, the catheter device used to perform the angioplasty or stent delivery is typically a single use, disposable product. If a drug infusion step is performed, it typically requires that another catheter device, such as the Dispatch(trademark) Coronary Infusion Catheter, sold by SciMed Life Systems, Maple Grove, Minn., be inserted in the body vessel.
A drawback of drug delivery devices such as the Dispatch(trademark) catheter is the special-purpose nature of such devices. For example, while the drug delivery device may contain many parts in common with the catheter device used in the original angioplasty or stent delivery procedure, the drug delivery device may typically only be used after another instrument first has been used to treat the body vessel.
In addition, special purpose drug delivery devices require manufacturing, purchasing and handling costs beyond those required to perform the treatment procedure. For example, to provide a properly sized balloon-style drug delivery device for each application, a hospital or clinic must carry a complete inventory of such drug delivery devices, with an entire range of balloon diameters and drug delivery pore sizes, as may be required for occasional use.
Alternatively, combination angioplasty/drug infusion devices have been developed, as are described, for example, in U.S. Pat. No. 5,415,367 and PCT International Publication No. WO 94/21320. These devices are used both for performing an angioplasty procedure and for accomplishing a drug infusion step. A drawback of such devices, however, is the additional cost and specialized structure required to permit a single device to accomplish both the angioplasty and drug delivery tasks.
In view of the foregoing, it would be desirable to provide methods and apparatus that permit re-use of some or all of the components of a catheter device used in an initial treatment procedure, so that the components of the catheter device may be re-used in a drug infusion procedure.
It would further be desirable to provide low cost and easy-to-use methods and apparatus for modifying previously known angioplasty catheters and similar types of catheter devices for use in providing a drug infusion device.
It would further be desirable to provide low cost and easy-to-use methods and apparatus that permit conversion of previously known catheters, for example, angioplasty balloon catheters, into drug infusion devices on an as-needed basis, thereby eliminating the cost and handling problems associated with stocking an inventory of different types of drug delivery devices.
In view of the foregoing, it is an object of this invention to provide methods and apparatus that permit re-use of some or all of the components of a catheter device used in an initial treatment procedure, so that the components of the catheter device may be re-used in a drug infusion procedure.
It is a further object of the present invention to provide low cost and easy-to-use methods and apparatus for modifying previously known angioplasty catheters and similar types of catheter devices for use in providing a drug infusion device.
It is another object of this invention to provide low cost and easy-to-use methods and apparatus that permit conversion of previously known catheters, for example, angioplasty balloon catheters, into drug infusion devices on an as-needed basis, thereby eliminating the cost and handling problems associated with stocking an inventory of different types of drug delivery devices.
These and other objects of the invention are accomplished in accordance with the principles of the invention by providing methods and apparatus for modifying a catheter device, either previously unused or used, into a drug infusion device for intraluminal or endoluminal use on an as-needed basis. In accordance with the invention, methods and apparatus are provided for rapidly perforating, in a sterile environment, a standard catheter, or balloon of a balloon catheter, to permit the device to be used for a drug infusion task.
The apparatus of the present invention includes means for defining a cavity for receiving a catheter, and perforation means extending within the cavity for generating a plurality of perforations in the catheter either mechanically or electrically. The apparatus may be easily operated in a sterile catheterization environment, for example, on a angioplasty equipment table, without requiring any particular skill. When a drug or therapeutic agent, either a liquid, gas or solid suspension of drug eluting solids, is subsequently injected into the catheter, the drug or therapeutic agent exits the catheter through the perforations in a controlled manner.
In accordance with a first family of embodiments of the present invention, a plurality of pins are provided on at least one member of a pair of opposing members defining a cavity to receive a catheter. When the members are closed together about a catheter of either standard or balloon construction, the plurality of pins perforate the catheter.
In accordance with a second family of embodiments of the present invention, apparatus is provided having a cavity for receiving a catheter and holding the catheter in a predetermined relation to cam-actuated perforation means. Means are also provided for adapting the apparatus of the present invention for converting a wide range of sizes of previously known catheter devices to drug delivery devices, on an as-needed basis.
In accordance with the present invention, the apparatus of the present invention may be constructed of rugged materials permitting repeated re-sterilization and re-use. Alternatively, the apparatus of the present invention may be constructed of low cost materials to provide a sterile, single-use, disposable product.
Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments.